Reactions of polycyclic thioketones with a phosphonylated carbanion

Abstract

AbstractPolycyclic, nonenolizable cycloaliphatic thioketones 1a and 1b react smoothly with the lithium salt of diethyl methylphosphonate 7 in THF solution at −40°C to afford products of the carbophilic attack exclusively. Quenching of the obtained lithium thiolates with alkyl iodides yields sulfanes of type 9 or 11, respectively, in good yields. 1‐Fluoro‐2,4‐dinitrobenzene was shown to act as an arylating agent. In the case of the “cage” thioketone 1b, the carbanion of salt 7 approaches the CS bond from the exo‐side exclusively. In contrast to the parent carbonyl compounds, thioketones 1 show no tendency to undergo the conversion analogous to the Horner–Wadsworth–Emmons reaction, which would result in the formation of an olefinic product. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:182–187, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20390